@article{25902, abstract = {{This Special Issue on “Functional Nanoporous Materials” in the MDPI journal nanomaterials features seven original papers ...}}, author = {{Weinberger, Christian and Tiemann, Michael}}, issn = {{2079-4991}}, journal = {{Nanomaterials}}, title = {{{Functional Nanoporous Materials}}}, doi = {{10.3390/nano10040699}}, year = {{2020}}, } @article{43747, abstract = {{Vortices are topological objects representing the circular motion of a fluid. With their additional degree of freedom, the vorticity, they have been widely investigated in many physical systems and different materials for fundamental interest and for applications in data storage and information processing. Vortices have also been observed in non-equilibrium exciton-polariton condensates in planar semiconductor microcavities. There they appear spontaneously or can be created and pinned in space using ring-shaped optical excitation profiles. However, using the vortex state for information processing not only requires creation of a vortex but also efficient control over the vortex after its creation. Here we demonstrate a simple approach to control and switch a localized polariton vortex between opposite states. In our scheme, both the optical control of vorticity and its detection through the orbital angular momentum of the emitted light are implemented in a robust and practical manner.}}, author = {{Meier, Torsten and Ma, Xuekai and Berger, Bernd and Aßmann, Marc and Driben, Rodislav and Schneider, Christian and Höfling, Sven and Schumacher, Stefan}}, journal = {{Nature communications}}, number = {{1}}, pages = {{897}}, publisher = {{Nature Publishing Group UK}}, title = {{{Realization of all-optical vortex switching in exciton-polariton condensates}}}, doi = {{10.1038/s41467-020-14702-5}}, volume = {{11}}, year = {{2020}}, } @inproceedings{42892, abstract = {{This paper presents the results of static short-term and long-term tensile tests for beta-nucleated joined polypropylene samples by the hot plate welding process. In the present study different dimensionless joining displacements are accounted for. The results show that high short-term tensile strength does not directly transfer to high long-term tensile strength. The morphology of the weld seam in the joined samples is examined by means of transmitted and reflected light microscopy. For the dimensionless joining displacements of 0.75 and 0.95, stretched spherulites are obtained. X-Ray diffraction can be used as a tool for qualitative and quantitative analysis and eventually for differentiation of samples of various joining displacements.}}, author = {{Wübbeke, Andrea and Schöppner, Volker and Paul, André and Tiemann, Michael and Austermeier, Laura and Fitze, Marcus and Chen, Mingie and Jakob, Fabian and Heim, Hans-Peter and Wu, Tao and Niendorf, Thomas and Röhricht, Marie-Luise and Schmidt, Michael}}, booktitle = {{SPE ANTEC 2020: The Virtual Edition 5 }}, title = {{{Long- and Short-Term Tensile Strength and Morphology of Joined Beta-Nucleated Polypropylene Parts}}}, year = {{2020}}, } @article{24236, abstract = {{In diesem Artikel werden das Scherzugverhalten und der morphologische Zustand von konturgeschweißtem Polypropylen (PP) mit einem Massenanteil von 0,2% Ruß untersucht. Dabei zeigen die Ergebnisse ...}}, author = {{Schöppner, Volker and Wübbeke, Andrea and Schriegel, Fabian and Paul, Andrej and Tiemann, Michael and Geißler, Bastian and Schmidt, Michael and Magnier, Arnaud and Niendorf, Thomas }}, journal = {{Joining Plastics}}, pages = {{30--35}}, title = {{{Selected Aspects for the Assessment of Laser Transmission Welding}}}, year = {{2020}}, } @article{44995, author = {{Dreßler, C. and Kabbe, G. and Brehm, Martin and Sebastiani, D.}}, journal = {{J. Chem. Phys.}}, pages = {{164110}}, title = {{{Exploring Non-Equilibrium Molecular Dynamics of Mobile Protons in the Solid Acid CsH2PO4 on the Micrometer and Microsecond Scale}}}, doi = {{10.1063/5.0002167}}, volume = {{152 (16)}}, year = {{2020}}, } @article{44997, author = {{Brehm, Martin and Radicke, J. and Pulst, M. and Shaabani, F. and Sebastiani, D. and Kressler, J.}}, journal = {{Molecules}}, pages = {{3539}}, title = {{{Dissolving Cellulose in 1,2,3-Triazolium- and Imidazolium-Based Ionic Liquids with Aromatic Anions}}}, doi = {{10.3390/molecules25153539}}, volume = {{25 (15)}}, year = {{2020}}, } @article{44998, author = {{Hunold, J. and Eisermann, J. and Brehm, Martin and Hinderberger, D.}}, journal = {{J. Phys. Chem. B}}, pages = {{8601--8609}}, title = {{{Characterization of Aqueous Lower Polarity Solvation Shells Around Amphiphilic TEMPO Radicals in Water}}}, doi = {{10.1021/acs.jpcb.0c04863}}, volume = {{124 (39)}}, year = {{2020}}, } @article{44993, author = {{Scarbath-Evers, L. and Hammer, R. and Golze, D. and Brehm, Martin and Sebastiani, D. and Widdra, W.}}, journal = {{Nanoscale}}, pages = {{3834--3845}}, title = {{{From Flat to Tilted: Gradual Interfaces in Organic Thin Film Growth}}}, doi = {{10.1039/C9NR06592J}}, volume = {{12}}, year = {{2020}}, } @article{44994, author = {{Dreßler, C. and Kabbe, G. and Brehm, Martin and Sebastiani, D.}}, journal = {{J. Chem. Phys.}}, pages = {{114114}}, title = {{{Dynamical Matrix Propagator Scheme for Large-Scale Proton Dynamics Simulations}}}, doi = {{10.1063/1.5140635}}, volume = {{152 (11)}}, year = {{2020}}, } @article{44999, author = {{Weiß, M. and Brehm, Martin}}, journal = {{Molecules}}, pages = {{5861}}, title = {{{Exploring Free Energy Profiles of Enantioselective Organocatalytic Aldol Reactions under Full Solvent Influence}}}, doi = {{10.3390/molecules25245861}}, volume = {{25 (24)}}, year = {{2020}}, } @article{44996, author = {{Brehm, Martin and Thomas, M. and Gehrke, S. and Kirchner, B.}}, journal = {{J. Chem. Phys.}}, pages = {{164105}}, title = {{{TRAVIS – A Free Analyzer for Trajectories from Molecular Simulation}}}, doi = {{10.1063/5.0005078}}, volume = {{152 (16)}}, year = {{2020}}, } @article{24100, abstract = {{Zinc oxide (ZnO) hollow spheres with defined morphology and micro-/nanostructure are prepared by a hydrothermal synthesis approach. The materials possess fine-leaved structures at their particle surface (nanowall hollow micro spheres). Morphology control is achieved by citric acid used as an additive in variable relative quantities during the synthesis. The structure formation is studied by various time-dependent ex situ methods, such as scanning electron microscopy, x-ray diffraction, and Raman spectroscopy. The fine-leaved surface structure is characterized by high-resolution transmission electron microscopy techniques (HRTEM, STEM), using a high-angle annular dark field detector, as well as by differential phase contrast analysis. In-depth structural characterization of the nanowalls by drop-by-drop ex situ FE-SEM analysis provides insight into possible structure formation mechanisms. Further investigation addresses the thermal stability of the particle morphology and the enhancement of the surface-to-volume ratio by heat treatment (examined by N2 physisorption).}}, author = {{Engelkemeier, Katja and Lindner, Jörg and Bürger, Julius and Vaupel, Kathrin and Hartmann, Marc and Tiemann, Michael and Hoyer, Kay-Peter and Schaper, Mirko}}, issn = {{0957-4484}}, journal = {{Nanotechnology}}, pages = {{095701}}, title = {{{Nano-architectural complexity of zinc oxide nanowall hollow microspheres and their structural properties}}}, doi = {{10.1088/1361-6528/ab55bc}}, volume = {{31}}, year = {{2020}}, } @article{16277, abstract = {{CP2K is an open source electronic structure and molecular dynamics software package to perform atomistic simulations of solid-state, liquid, molecular, and biological systems. It is especially aimed at massively parallel and linear-scaling electronic structure methods and state-of-theart ab initio molecular dynamics simulations. Excellent performance for electronic structure calculations is achieved using novel algorithms implemented for modern high-performance computing systems. This review revisits the main capabilities of CP2K to perform efficient and accurate electronic structure simulations. The emphasis is put on density functional theory and multiple post–Hartree–Fock methods using the Gaussian and plane wave approach and its augmented all-electron extension.}}, author = {{Kühne, Thomas and Iannuzzi, Marcella and Ben, Mauro Del and Rybkin, Vladimir V. and Seewald, Patrick and Stein, Frederick and Laino, Teodoro and Khaliullin, Rustam Z. and Schütt, Ole and Schiffmann, Florian and Golze, Dorothea and Wilhelm, Jan and Chulkov, Sergey and Mohammad Hossein Bani-Hashemian, Mohammad Hossein Bani-Hashemian and Weber, Valéry and Borstnik, Urban and Taillefumier, Mathieu and Jakobovits, Alice Shoshana and Lazzaro, Alfio and Pabst, Hans and Müller, Tiziano and Schade, Robert and Guidon, Manuel and Andermatt, Samuel and Holmberg, Nico and Schenter, Gregory K. and Hehn, Anna and Bussy, Augustin and Belleflamme, Fabian and Tabacchi, Gloria and Glöß, Andreas and Lass, Michael and Bethune, Iain and Mundy, Christopher J. and Plessl, Christian and Watkins, Matt and VandeVondele, Joost and Krack, Matthias and Hutter, Jürg}}, journal = {{The Journal of Chemical Physics}}, number = {{19}}, title = {{{CP2K: An electronic structure and molecular dynamics software package - Quickstep: Efficient and accurate electronic structure calculations}}}, doi = {{10.1063/5.0007045}}, volume = {{152}}, year = {{2020}}, } @inproceedings{16898, abstract = {{Electronic structure calculations based on density-functional theory (DFT) represent a significant part of today's HPC workloads and pose high demands on high-performance computing resources. To perform these quantum-mechanical DFT calculations on complex large-scale systems, so-called linear scaling methods instead of conventional cubic scaling methods are required. In this work, we take up the idea of the submatrix method and apply it to the DFT computations in the software package CP2K. For that purpose, we transform the underlying numeric operations on distributed, large, sparse matrices into computations on local, much smaller and nearly dense matrices. This allows us to exploit the full floating-point performance of modern CPUs and to make use of dedicated accelerator hardware, where performance has been limited by memory bandwidth before. We demonstrate both functionality and performance of our implementation and show how it can be accelerated with GPUs and FPGAs.}}, author = {{Lass, Michael and Schade, Robert and Kühne, Thomas and Plessl, Christian}}, booktitle = {{Proc. International Conference for High Performance Computing, Networking, Storage and Analysis (SC)}}, location = {{Atlanta, GA, US}}, pages = {{1127--1140}}, publisher = {{IEEE Computer Society}}, title = {{{A Submatrix-Based Method for Approximate Matrix Function Evaluation in the Quantum Chemistry Code CP2K}}}, doi = {{10.1109/SC41405.2020.00084}}, year = {{2020}}, } @unpublished{40994, abstract = {{Photoactive compounds are essential for photocatalytic and luminescent applications, such as photoredox catalysis or light emitting diodes. However, the substitution of noble metals, which are almost exclusively used, by base metals remains a major challenge on the way to a more sustainable world.1 Iron is a dream candidate for this ambitious aim.2 But compared to noble metal complexes that show long-lived metal-to-ligand charge-transfer (MLCT) states, realization of emissive and photoactive iron complexes is demanding, due to the fast deactivation of charge transfer states into non-emissive inactive states. No MLCT emission has been observed for monometallic iron complexes before. Consequently, dual emission could also not yet be realized with iron complexes, as it is a very rare property even of noble metal compounds. Here we report the FeIII complex [Fe(ImP)2][PF6] (HImP = 1,1’-(1,3-phenylene)bis(3-methyl-1-imidazol-2-ylidene)), showing Janus-type dual emission by combining LMCT (ligand-to-metal charge transfer) with MLCT luminescence. The respective excited states are characterized by a record lifetime of τMLCT = 4.2 ns, and a moderate τLMCT = 0.2 ns. Only two emissive FeIII compounds are known so far and they show LMCT luminescence only.3,4 The unique properties of the presented complex are caused by the specific ligand design combining four N-heterocyclic carbenes with two cyclometalating groups, using the σ-donor strength of six carbon atoms and the acceptor capabilities of the central phenyl rings. Spectroscopically, doublet manifolds could be identified in the deactivation process, while (TD)DFT analysis revealed the presence of quartets as well. With three key advancements of realizing the first iron complex showing dual luminescence, a MLCT luminescence and a world record MLCT lifetime, the results constitute a basis for future application of iron complexes as white light emitters and new photocatalytic reactions making use of the Janus-type properties of the developed complex.}}, author = {{Bauer, Matthias and Steube, Jakob and Päpcke, Ayla and Bokareva, Olga and Reuter, Thomas and Demeshko, Serhiy and Schoch, Roland and Hohloch, Stephan and Meyer, Franc and Heinze, Katja and Kühn, Oliver and Lochbrunner, Stefan}}, publisher = {{Research Square Platform LLC}}, title = {{{Janus-type dual emission of a Cyclometalated Iron(III) complex}}}, year = {{2020}}, } @article{12878, abstract = {{In scientific computing, the acceleration of atomistic computer simulations by means of custom hardware is finding ever-growing application. A major limitation, however, is that the high efficiency in terms of performance and low power consumption entails the massive usage of low precision computing units. Here, based on the approximate computing paradigm, we present an algorithmic method to compensate for numerical inaccuracies due to low accuracy arithmetic operations rigorously, yet still obtaining exact expectation values using a properly modified Langevin-type equation.}}, author = {{Rengaraj, Varadarajan and Lass, Michael and Plessl, Christian and Kühne, Thomas}}, journal = {{Computation}}, number = {{2}}, publisher = {{MDPI}}, title = {{{Accurate Sampling with Noisy Forces from Approximate Computing}}}, doi = {{10.3390/computation8020039}}, volume = {{8}}, year = {{2020}}, } @article{41025, abstract = {{We investigate the structure-activity correlations of methanation catalysts obtained by thermal decomposition of a Ni-based metal-organic framework, using pair distribution function, X-ray absorption spectroscopy and X-ray diffraction.}}, author = {{Prinz, Nils and Schwensow, Leif and Strübbe, Sven and Jentys, Andreas and Bauer, Matthias and Kleist, Wolfgang and Zobel, Mirijam}}, issn = {{2040-3364}}, journal = {{Nanoscale}}, keywords = {{Xray, Catalysis}}, number = {{29}}, pages = {{15800--15813}}, publisher = {{Royal Society of Chemistry (RSC)}}, title = {{{Hard X-ray-based techniques for structural investigations of CO2 methanation catalysts prepared by MOF decomposition}}}, doi = {{10.1039/d0nr01750g}}, volume = {{12}}, year = {{2020}}, } @article{62101, abstract = {{AbstractThe carbon–carbon double bond of unsaturated carbonyl compounds was readily reduced by using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl‐substituted phosphetane oxide was employed as the catalyst. The procedure is highly selective towards activated double bonds, tolerating a variety of functional groups that are usually prone to reduction. In total, 25 alkenes and two alkynes were hydrogenated to the corresponding alkanes in excellent yields of up to 99 %. Notably, less active poly(methylhydrosiloxane) could also be utilized as the terminal reductant. Mechanistic investigations revealed the phosphane as the catalyst resting state and a protonation/deprotonation sequence as the crucial step in the catalytic cycle.}}, author = {{Longwitz, Lars and Werner, Thomas}}, issn = {{0044-8249}}, journal = {{Angewandte Chemie}}, keywords = {{T2, T4}}, number = {{7}}, pages = {{2782--2785}}, publisher = {{Wiley}}, title = {{{Reduction of Activated Alkenes by PIII/PV Redox Cycling Catalysis}}}, doi = {{10.1002/ange.201912991}}, volume = {{132}}, year = {{2020}}, } @misc{62147, author = {{Werner, Thomas and Stefanow, V. and Grandane, A. and Panten, J. and Eh, M.}}, keywords = {{T4}}, title = {{{Novel processes for preparing cis-cedrandiol}}}, year = {{2020}}, } @article{37956, author = {{Andexer, Jennifer N. and Beifuss, Uwe and Beuerle, Florian and Brasholz, Malte and Breinbauer, Rolf and Ernst, Martin and Greb, Julian and Gulder, Tobias and Hüttel, Wolfgang and Kath‐Schorr, Stephanie and Kordes, Markus and Lehmann, Matthias and Lindel, Thomas and Luy, Burkhard and Mück‐Lichtenfeld, Christian and Muhle, Claudia and Narine, Arun and Niemeyer, Jörg and Paradies, Jan and Pfau, Roland and Pietruszka, Jörg and Schaschke, Norbert and Senge, Mathias and Straub, Bernd F. and Werner, Thomas and Werz, Daniel B. and Winter, Christian}}, issn = {{1439-9598}}, journal = {{Nachrichten aus der Chemie}}, keywords = {{General Chemical Engineering, General Chemistry}}, number = {{3}}, pages = {{42--72}}, publisher = {{Wiley}}, title = {{{Organische Chemie}}}, doi = {{10.1002/nadc.20204095515}}, volume = {{68}}, year = {{2020}}, }